Revert of Revert of Move DstCopy on gpu into the GrXferProcessor. (patchset #1 id:1 of https://codereview.chromium.org/901663007/)

Reason for revert:
The revert didn't help the 10.9 bot. Unreverting by reverting the revert (which is basically relanding the original patch which itself was a revert of a revert). Revert.

Original issue's description:
> Revert of Move DstCopy on gpu into the GrXferProcessor. (patchset #11 id:200001 of https://codereview.chromium.org/885923002/)
>
> Reason for revert:
> Testing to see if reverting fixes 10.9 bots.
>
> Original issue's description:
> > Move DstCopy on gpu into the GrXferProcessor.
> >
> > BUG=skia:
> >
> > Committed: https://skia.googlesource.com/skia/+/74a11753604768bf461b80cabb66060e8564d82c
> >
> > Committed: https://skia.googlesource.com/skia/+/5e1378d0e075a323144ba14e0a4cbcca35eccc69
>
> TBR=joshualitt@google.com,egdaniel@google.com
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/21b2c53218ab25f4268e3992e51d916076a2a7ee

TBR=joshualitt@google.com,egdaniel@google.com
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/873723009

4 files changed, 2 insertions, 61 deletions

diff --git a/src/gpu/gl/builders/GrGLFragmentShaderBuilder.cpp b/src/gpu/gl/builders/GrGLFragmentShaderBuilder.cpp
index 61932f3084..86c622d456 100644
--- a/src/gpu/gl/builders/GrGLFragmentShaderBuilder.cpp
+++ b/src/gpu/gl/builders/GrGLFragmentShaderBuilder.cpp
@@ -179,56 +179,9 @@ const char* GrGLFragmentShaderBuilder::dstColor() {
             fbFetchColorName = declared_color_output_name();
         }
         return fbFetchColorName;
-    } else if (fProgramBuilder->fUniformHandles.fDstCopySamplerUni.isValid()) {
-        return kDstCopyColorName;
-    } else {
-        return "";
-    }
-}
-
-void GrGLFragmentShaderBuilder::emitCodeToReadDstTexture() {
-    bool topDown = SkToBool(kTopLeftOrigin_DstReadKeyBit & fProgramBuilder->header().fDstReadKey);
-    const char* dstCopyTopLeftName;
-    const char* dstCopyCoordScaleName;
-    const char* dstCopySamplerName;
-    uint32_t configMask;
-    if (SkToBool(kUseAlphaConfig_DstReadKeyBit & fProgramBuilder->header().fDstReadKey)) {
-        configMask = kA_GrColorComponentFlag;
     } else {
-        configMask = kRGBA_GrColorComponentFlags;
-    }
-    fProgramBuilder->fUniformHandles.fDstCopySamplerUni =
-            fProgramBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
-                                        kSampler2D_GrSLType,
-                                        kDefault_GrSLPrecision,
-                                        "DstCopySampler",
-                                        &dstCopySamplerName);
-    fProgramBuilder->fUniformHandles.fDstCopyTopLeftUni =
-            fProgramBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
-                                        kVec2f_GrSLType,
-                                        kDefault_GrSLPrecision,
-                                        "DstCopyUpperLeft",
-                                        &dstCopyTopLeftName);
-    fProgramBuilder->fUniformHandles.fDstCopyScaleUni =
-            fProgramBuilder->addUniform(GrGLProgramBuilder::kFragment_Visibility,
-                                        kVec2f_GrSLType,
-                                        kDefault_GrSLPrecision,
-                                        "DstCopyCoordScale",
-                                        &dstCopyCoordScaleName);
-    const char* fragPos = this->fragmentPosition();
-
-    this->codeAppend("// Read color from copy of the destination.\n");
-    this->codeAppendf("vec2 _dstTexCoord = (%s.xy - %s) * %s;",
-                      fragPos, dstCopyTopLeftName, dstCopyCoordScaleName);
-    if (!topDown) {
-        this->codeAppend("_dstTexCoord.y = 1.0 - _dstTexCoord.y;");
-    }
-    this->codeAppendf("vec4 %s = ", GrGLFragmentShaderBuilder::kDstCopyColorName);
-    this->appendTextureLookup(dstCopySamplerName,
-                              "_dstTexCoord",
-                              configMask,
-                              "rgba");
-    this->codeAppend(";");
+        return kDstCopyColorName;
+    } 
 }
 
 void GrGLFragmentShaderBuilder::enableCustomOutput() {
diff --git a/src/gpu/gl/builders/GrGLFragmentShaderBuilder.h b/src/gpu/gl/builders/GrGLFragmentShaderBuilder.h
index 688bbe6269..903c5e1d7b 100644
--- a/src/gpu/gl/builders/GrGLFragmentShaderBuilder.h
+++ b/src/gpu/gl/builders/GrGLFragmentShaderBuilder.h
@@ -97,7 +97,6 @@ public:
 
 private:
     // Private public interface, used by GrGLProgramBuilder to build a fragment shader
-    void emitCodeToReadDstTexture();
     void enableCustomOutput();
     void enableSecondaryOutput();
     const char* getPrimaryColorOutputName() const;
diff --git a/src/gpu/gl/builders/GrGLProgramBuilder.cpp b/src/gpu/gl/builders/GrGLProgramBuilder.cpp
index 088169622c..bb278be395 100644
--- a/src/gpu/gl/builders/GrGLProgramBuilder.cpp
+++ b/src/gpu/gl/builders/GrGLProgramBuilder.cpp
@@ -56,12 +56,6 @@ GrGLProgram* GrGLProgramBuilder::CreateProgram(const DrawArgs& args, GrGLGpu* gp
 
     GrGLProgramBuilder* pb = builder.get();
 
-    // emit code to read the dst copy texture, if necessary
-    if (GrGLFragmentShaderBuilder::kNoDstRead_DstReadKey != pb->header().fDstReadKey &&
-        !gpu->glCaps().fbFetchSupport()) {
-        pb->fFS.emitCodeToReadDstTexture();
-    }
-
     // TODO: Once all stages can handle taking a float or vec4 and correctly handling them we can
     // seed correctly here
     GrGLSLExpr4 inputColor;
diff --git a/src/gpu/gl/builders/GrGLProgramBuilder.h b/src/gpu/gl/builders/GrGLProgramBuilder.h
index 4b40cefad0..a9288cc9b0 100644
--- a/src/gpu/gl/builders/GrGLProgramBuilder.h
+++ b/src/gpu/gl/builders/GrGLProgramBuilder.h
@@ -267,11 +267,6 @@ public:
         // We use the render target height to provide a y-down frag coord when specifying
         // origin_upper_left is not supported.
         UniformHandle       fRTHeightUni;
-
-        // Uniforms for computing texture coords to do the dst-copy lookup
-        UniformHandle       fDstCopyTopLeftUni;
-        UniformHandle       fDstCopyScaleUni;
-        UniformHandle       fDstCopySamplerUni;
     };
 
 protected: